Tracked live by the FAA, but its flight plan was first seen after takeoff, so we don't know the scheduled time and can't say whether it's late.

JETBLUE · FLIGHT B6 1578 IN THE AIR (OFF 12:23 PM PT, ETA 7:53 PM ET) · SCHEDULED TIME UNKNOWN
Today

B6 1578 · LAS → BOS

took off 12:23 PM PT · expected to land 7:53 PM ET (scheduled time unknown)
Forecast issued Tue 5:00 PM ET · 2h after departure

Odds over time

Arrive at BOS more than 15 minutes late?
65% chance · ±2 pts – · 24h
HOW SURE WE ARE Very high. The odds now come almost entirely from live conditions.
WEATHER FORECASTS LIVE IN THE AIR 0% 25% 50% 75% 100% 14h 12h 6h Departs Now Lands